On the other hand, the phase space \(\mathbb {S}\)  is isomorphic to a 2-dimensional (2D) gauge-fixed surface \(\hat{\Gamma }\)  of \(\bar{\Gamma }\) , which is intersected by each dynamical trajectory once and only once [1]}. From the FR equations, it can be shown that for both mLQC-I and mLQC-II the variable \(b\)  satisfies the equation [2]}, [3]}, [4]},
\(\dot{b} = - 4\pi G \gamma (\rho + P).\) 
